酪蛋白水解产物对含益生菌酸奶中益生菌数量的影响

本文研究了牛奶蛋白水解产物对发酵牛奶中益生菌生长的促进作用，并对在两周的贮存期内活性益生菌菌数的稳定性进行了比较研究。实验以益生菌菌株一嗜酸乳杆菌作为研究用菌种。利用novo型碱性蛋白酶水解酪蛋白获得水解度分别为4．7％、7．1％、8．8％、10．1％、12．6％的酪蛋白水解产物，研究以0．5、1、2和4g／L四个添加水平加入发酵酸奶中，分析其对益生菌生长情况的影响。结果证明，酪蛋白水解产物的添加普遍促进了嗜酸乳杆菌在酸奶中的生长。随着添加量的增加，嗜酸乳杆菌在发酵牛奶中的稳定性得到了同步提高。但综合分析，水解度为8.8％的水解产物，添加量为2g／L时，可使益生菌的生长活性和稳定性状态最佳。研究结果证实，选择优化的酪蛋白水解产物对发酵牛奶中益生菌的生长及维持其生存能力均会产生积极地促进作用，也对发酵乳行业生产符合国际标准的益生菌产品具有重要的理论和实践的价值。

Effect of Casein Hydrolysates on Cell Count and Microbiological Stability of Fermented Milks Containing Probiotic Bacteria

In the present work, the effect of milk protein hydrolysates on probiotic cell counts and its stability during two weeks storage was studied. Probiotic bacteria, LactobaciUus acidophillus was used as pure culture. Proteolytic enzyme, alcalase novo was used to hydrolyze casein. The effect of five casein hydrolysates, which have a degree of hydrolysis of 4.7%, 7.1%, 8.8%, 10.1%, 12.6% respectively, to the growth of L. acidophilus were investigated by adding them to milk at a concentration ranging from 0.5 to 4g/L. Addition of casein hydrolysates with different degrees of hydrolysis enhance the growth of probiotic bacteria L.acidophilus generally, With the increase in adding level the stability of L.acidophilus increased. However, the highest viability and best stability of Lacidophilus was observed when casein was hydrolyzed to the degree of 8.8% and added at the level of 2g/L. This result shows that the addition of casein hydrolysates has a positive effect on the probiotic cell count and microbiological stability of fermented milks containing probiotic bacteria when controlled wisely. The research work has an important theoretical and practical value by helping dairy industry meet international standards of probiotic products.